Cities wiped out, thousands of homes without electricity… On December 10, the United States was hit by “historic” tornadoes, which devastated entire regions of Kentucky, Illinois, Tennessee, Arkansas and Missouri. The impact of these disasters, which are becoming more frequent and devastating due to global warming, is all the greater when they affect cities.
The images are followed by astronomical figures: these disasters cause considerable reconstruction expenses and generate severe indirect costs. They disrupt the economy, permanently damage the attractiveness of the affected cities, strongly disrupt the real estate, land and insurance markets and exacerbate social inequalities in the face of risk. Cities can regain control by limiting the hazard – as in Japan, where anti-seismic standards reduce the impact of most earthquakes – and by developing disaster management strategies when disasters occur.
Their answer today can be summed up in one word: resilience.
A single word for a complex problem… Isn’t it a catch-all word? Resilience illustrates the ability to bounce back from a shock or disruption (resilere) and is distinct from resistance, defined as the ability to withstand a shock (stare). Resilience approaches turn away from the ambition of achieving zero risk and prefer the notion of acceptable risk and the development of the capacity to bounce back, organize and adapt. The city is thus seen as a dynamic system in constant search of a state of equilibrium.
As cities are interconnected systems, a shock wave can easily spread and disrupt the entire system. Resilience thus has a real mobilizing and potentially coordinating virtue for actors with very diverse interests. Why only potentially? Because not everyone understands the same thing under the term resilience and therefore does not necessarily pursue the same goal: what are the criteria for assessing whether a city is resilient or not? How long does it take to overcome a crisis to be declared resilient? What defines the state of equilibrium? Resilience is the support of standards. Only if these questions are asked can the actions of the various stakeholders be effectively coordinated. And a city can only become resilient if a consensus emerges on the nature of the risk that society agrees to bear.
→ To go further: our report on urban resilience